How to get rid of wrinkles
I think there are too many problem in your topology to be able to answer with few words, for example I see that there is a transversal edge, so I drag up a vertex that is supposed to correct the problem, now I see that you actually had several vertices overlaying, so you need to remove doubles, also you have many ngons, etc... 



For example, if you use the knife tool you can create quads and correct the topology: